Stud-pulling crane



Dec. 13, 1960 B. PEARSON Q 2,964,459

STUD-PULLING CRANE Filed May 29, 1956 17 Sheets-Sheet 1 u l 11-" i INVENTOR.

1 B 2 mad A Pearson ATTORNEYS Dec. 13, 1960 B. A. PEARSON STUD-PULLING cam:

17 Sneets-Sheet 2 Filed May 29, 1956 Dec. 13, 1960 B. A. PEARSON 2,964,459

STUD-PULLING CRANE Filed May 29, 1956 17 Shea t 3 INVENTOR. B Qmord A.'P zc1rson ATTORNEVS Dec. 13, 1960 B. A. PEARSON STUD-PULLING CRANE 1'7 Sheets-Sheet 4 Filed May 29, 1956 INVENTOR. Barnard APQQrson B W 1* m Dmw ATTORNEYb Dec. 13, 1960 B. A. PEARSON STUD-PULLING CRANE 17 Sheets-Sheet 5 Filed May 29, 1956 INVENTOR.

Af zora on I w A-r-ronwevs ////u /M//NM Dec. 13, 1960 B. A. PEARSON STUD-PULLING CRANE Filed May 29, 1956 llC 17 Sheets-Sheet 7 INVENTOR.

Bqrnard A.Wurson ATTORNEYS Dec. 13, 1960 B. A. PEARSON 2,964,459

STUD-PULLING CRANE Filed May 29, 1956 17 Sheets-Sheet 8 1B INVENTOR.

} Barnard A. Pearson A'r'romevs Dec. 13, 1960 B. A. PEARSON 2,964,459

STUD-PULLING CRANE Filed May 29, 1956 17 Sheets-Sheet 10 IN V EN TOR.

Barnard APmrson ATTORNEYS Dec. 13, 1960 B. A. PEARSON 2,964,459

STUD-PULLING CRANE Filed May 29, 1956 17 Sheets-Sheet 11 IN VEN TOR. Birnurd Hug-son ATTORNEYS Dec. 13, 1960 a. A. PEARSON 2,964,459

STUD-PULLING CRANE Filed May 29, 1956 17 Sheets-Sheet 13 I INVENTOR.

B B rnurd A. Pmrson ATToRNEvs Filed May 29, 1956 17 Sheets-Sheet 14 INVENTOR. Barnard APQQrsoO @M ATTORNEYS Dec. 13, 1960 B. A. PEARSON 2,964,459

STUD-PULLING CRANE Filed May 29, 1956 17 Sheets-Sheet 1s BY m Aw-roauevs Dec. 13, 1960 B. A. PEARSON 2,964,459

STUD-PULLING CRANE Filed May 29, 1956 17 Sheets-Sheet l6 INVENTOR. Barnard APacxrson Y m Aw-Toenevs Dec. 13, 1960 B. A. PEARSON STUD-PULLING CRANE 1'7 Sheets-Sheet 1'7 Filed May 29, 1956 INVENTOR. Bum-1rd A.'Paraon B kr'rowuevs United States Patent STUD-PULLING CRANE Bernard A. Pearson, Seattle, Wash., assignor to Ederer Engineering 00., Seattle, Wash, a corporation of Washington Filed May 29, 1956, Ser. No. 588,121

10 Claims. Cl. 204-194 This invention relates to a stud-pulling crane, and especially a crane for pulling the studs which are used to pass current into the carbon anodes of reduction cells employed in the production of aluminum. More especially still the invention pertains to a crane for both (1) pulling the studs, which involves the step of first breaking the stud loose from the encompassing block of carbon, and then lifting the freed stud clear of the carbon block, and (2) replacing the removed stud with a clean stud.

For its general object the invention aims to provide a crane which will perform its intended functions with unusual case and expedition.

As a further and important object the invention aims to provide a crane which is hydraulic in nature, and which is to say that the energy responsible for performing motions incident to pulling the studs and replacing the same is derived from a controlled pressure flow of oil.

The invention has the yet further important object of devising a stud-pulling crane in which parts of the crane which perform an elevating function in course of raising a pulled stud clear of the carbon block are telescopically and otherwise looking to the provision of a rugged studpulling crane which can be serviced with ease, all of which will appear and be understood in the following description and claims, the invention consists in the novel construction and in the adaptation and combination of parts hereinafter described and claimed.

In the accompanying drawings: Figure 1 is a fragmentary transverse vertical sectional 'view illustrating a stud-pulling crane constructed to embody the preferred teachings of the present invention, full and dotted lines being employed to indicate the elevatfing structure in a lowered and a raised condition. Studs :shown in this view are portrayed by broken lines.

Fig. 2 is a top plan view of the crane. Fig. 3 is a fragmentary view of the stud puller proper,

'shown partly in elevation and partly in section and with the scale appreciably larger than that employed in the preceding views. Incorporated in this view is a showing -of a stud.

Fig. 4 is a diagrammatic view showing the quarter-turn motion to which the stud puller admits.

Fig. 5 is a reduced-scale elevational view of the stud. Fig. 6 is a horizontal sectional view drawn to an enlarged view on line 6-6 of Fig. 5.

Fig. 7 is a fragmentary top plan view of one of the reduction cells with a broken-line illustration of the stud puller shown in position preparatory to pulling a stud.

Fig. 8 is a vertical sectional view of the reduction cell drawn to an enlarged scale on line 8-8 of Fig. 7.

Fig. 9 is a vertical sectional view on line 99 of Fig. 8.

Fig. 10 is a fragmentary top plan view of the stud puller proper.

Fig. 11 is a fragmentary vertical sectional view of the stud puller drawn on the jogged section line 11-11 of Fig. 15.

Fig. 12 is an enlarged scale view blowing up the circled detail designated by 12 in Fig. 11.

Fig. 13 is a similar view blowing up the circled detail designated by 13 in Fig. 11.

Fig. 14 is a fragmentary enlarged-scale horizontal section on line 14-14 of Fig. 11.

Fig. 15 is an enlarged-scale horizontal sectional View on line 15-15 of Fig. 11.

Fig. 16 is a fragmentary enlarged-scale vertical sectional view illustrating the lower or chuck end of the stud puller, and with the gripping fingers of the chuck in the Fig. 18 is a horizontal sectional view on line 1818 v of Fig. 16.

Fig. 19 is a view similar to Fig. 16 showing the gripping fingers of the chuck in an open condition.

Fig. 20 is a fragmentary vertical sectional view on line 2020 of Fig. 19.

Fig. 21 is an elevational view showing a fragmentary portion of the stud pullers lower end.

Fig. 22 is a horizontal sectional view on line 2222 of Fig. 20.

Fig. 23 is a horizontal sectional view on line 23-43 of Fig. 20.

Fig. 24 is a fragmentary perspective view of the upper end of the stud puller.

Figs. 25 and 26 are each fragmentary elevational views of the stud puller with parts in section, the two views portraying different degrees of telescoping action.

Fig. 27 is a fragmentary vertical sectional view of the rack in which replacement and used studs are stored.

Fig. 28 is a fragmentary horizontal sectional view drawn to an enlarged scale on line 28-28 of Fig. 27.

Fig. 29 is a fragmentary perspective view illustrating much the same structure as that shown in Fig. 28.

Fig. 30 is a fragmentary horizontal sectional view drawn to an enlarged scale on line 30--30 of Fig. 27.

Fig. 31 is an enlarged-scale detail vertical sectional view on line 3131 of Fig. 30.

Fig. 32 is a fragmentary vertical sectional view on line 3232 of Fig. 27.

Fig. 33 is a fragmentary elevational view of a hosecarrying reel structure employed in the present invention.

Fig. 34 is a fragmentary vertical sectional view on line 3434 of Fig. 33.

Fig. 35 is a fragmentary vertical sectional view on line 3535 of Fig. 34; and

Figs. 36 and 37 are views which, taken together, diagram the hydraulic circuit for the invention.

Before proceeding with a detailed description of the present invention it is believed that clarity in an understanding thereof may be advanced by here cursorily considering the work to be accomplished and generally outlining the structure which I provide for performing such work.

One process in the production of aluminum employs what is known as the Soderberg reduction cell, wherein a block of carbon which serves as an anode has embedded therein a multiplicity of studs. The studs carry current to the block and present exposed upper ends which are clamped to a bus bar. As the reduction process is carried on the lower face of the carbon block is gradually eroded and in compensation thereof, so that the gap between ,suchanode and a complementing cathode will remain constant, the block is mounted for vertical movement. There is a critical level below which the studs must not extend, wherefore it becomes necessary to withdraw the studs as their embedded ends reach this level. In order that the reduction process may not be interrupted it is the practice to have the studs extend to different depths within the carbon block so that current can continue to pass through upper studs as lower studs are removed. The studs have a moderate taper, and the removal procedure is one of first disengaging the clamping agent so as to free the stud from the bus bar, then imposing twisting and drawing forces upon the stud to break the bond between the stud and the hard carbon in which it is embedded, and finally withdrawing the stud by lifting the same free of the block. There is a hard residue crust of carbon upon each stud as it is removed, wherefore the studs must be cleaned before being returned to service. Upon removal of the studs liquid carbon enters the socket to fill the same, this liquid carbon occurring as a covering layer upon the block. A clean replacement stud is now inserted in this socket, albeit with its lower end at a given higher level, and excess liquid carbon is squeezed out from around such stud as the latter is lowered into the socket. The operation is completed by again clamping the applied stud to the bus bar. The stud-investing liquid carbon gradually hardens so as to become an integral part of the carbon block.

In performing the above work of breaking the bond between stud and block, extracting the freed stud, and inserting the replacement stud, the present invention provides a trolley supported by an overhead traveling crane, and carried by the trolley is a stud-pulling unit providing a telescoping leg having upon its lower end a stud-gripping chuck. The leg admits of having a twist imposed thereon, and it is a salient characteristic of the unit that the operations of activating the chuck, twisting the leg, and telescoping the leg are performed hydraulically. The invention provides a rack in which used studs are deposited, and from which fresh studs are drawn.

In the accompanying drawings the anode-forming carbon block in which the studs are embedded is denoted by the numeral 50. One such block is provided for each cell. From an inspection of Figs. 5 through 9, it will be seen that each stud 51 is tapered and at its upper end has a reduced head 52 cut away, as at 53, to furnish diametrically opposite flats the purpose of which is to fit in a correspondingly shaped socket of the chuck and secure the stud against rotation relative to the chuck. Immediately above these flats the heads are notched, as at 54, to re ceive jaws of the chuck, and below the flats 53 there is provided a flat face 55. An L-shaped extension 57 has its foot 56 seated against and integrally secured to said face 55. The upright leg of this L-shaped extension, when viewed from above, lies angular to the foot and is directed away from the stud in a plane tangent or approximately tangent thereto, and in use is arranged to be clamped against the bus bar. There are two pairs of these bus bars, designated by 58 and 59, for each cell, and the arrangement is one in which the two bars of each pair are placed back-to-back with a plurality of studs being clamped to the outer face of each bar. Viewing a cell in plan (see Fig. 7) and from a vantage point at one end thereof so that the two bars of each pair can be said to be right and left hand bars, it will be seen that the studs in the left hand row are turned approximately 180 from the studs in the right hand row.

The traveling crane of the present invention provides the usual trucks 60 riding on longitudinally extending overhead tracks 61, and has a pair of girders 62 extending transversely between these trucks, the girders being transversely spaced and having the opening which lies therebetween unobstructed other than for a stirrup 63 on which the above-mentioned rack, designated generally by 4-9, is arranged to seat. This stirrup lies at or about the midwidth of the crane and the seat proper lies well below the girders and carries a set of rollers 64 on which the rack bears. These rollers are journaled to rotate about horizontal axes and are located at spaced intervals on the circumference of a circle taken about the center of the stirrup as an axis, and are complemented by a set of rollers 65 journaled to turn about vertical axes spaced at intervals of the circumference of a circle concentric with and larger than the above-mentioned circle. The rack has an annular base plate 66 which seats upon the rollers 64 and bears by its outer rim against the rollers 65' and at the inner perimeter such plate presents a downturned flange formed upon its lower edge with rack teeth 69. A stirrup-carried gear 67 meshes this rack, and powering the gear is a motor 68; In order that the operator may stop the rack 49 in positions which will assure proper registration with the chuck, there is provided a visual indicator comprised of an electrically-energized signal light (not shown) which is included in a normally open circuit closed by a limit switch 70 (see Fig. 30) engaged by a nodular projection 71 formed upon each of a plurality of cups 72 carried by the rack. These cups, which are each adapted to receive the lower end of a respective stud, occur at the base of the rack and are placed at uniformly spaced intervals of the circumference. At the top of the rack such cups are each complemented by a coaxially placed semi-circular socket 73 cut in an annular head flange 74. As an adjunct to each of said sockets there is welded to the face of the head flange a respective positioning plate 75; and on each of these plates are two positioning lugs '76 and 77. The function of the positioning plates and their surmounting lugs is to engage the sectionally angle-shaped foot portions of the stud extensions 57, and by such engagement localize the rackcarried studs in a selected one of two fixed rotary positions. The shape and placement of such plates and lugs can be best seen from an inspection of Fig. 28 wherein the two positions are shown by dotted lines and wiil be hereinafter termed Position A and Position B. Consider that part of the foot which bears against and is fixed to the stud as the toe portion and the angular projection thereof as the heel portion. When occupying Position A, said toe is located approximately radial to the center of the rack, and the heel is to the inside. The toe now lies between one end of one positioning plate and the other end of another positioning plate, seating directly upon the flange. When occupying Position B, the stud is turned 90 from the A position in a counterclockwise direction, placing the toe approximately tangent to a circle taken about the center of the rack and with the heel directed inwardly radial to such center. In this position the foot seats upon a positioning plate 75 and locates the toe between the related two lugs 76 and 77. The significance of these two positions will become apparent in course of describing the functioning of the stud puller, but suffice it to here say that such positions are determined by whether the stud in question is to be applied to a left or to a right hand bus bar. For loading the rack with fresh studs the procedure is to remove the rack bodily and transport the same to and from the loading station, the trolley of the crane being equipped with a hook 80 for performing this function.

Said trolley for the crane is denoted generally by 81, and the track rails therefor are designated by 82, such rails extending transversely of the crane one on one and the other on the other of the two girders 62. A cab 83 for the driver of the trolley is hung from an outrigger extension of the trolley frame 84.

Bolted as at 85 to the frame 84 and in a manner (see Fig. 13) which electrically insulates the same from the frame there is provided an upstanding cylindrical shell 86 open at the top and bottom, and made a rigid part of this shell and projecting well beyond the same at diametrically opposite sides is a surmounting head %7. This head provides a purchase for two opposingly mounted double-acting oil cylinders 88 whose pistons act through connecting rods 89 to impart a quarter turn to a crank ring 90, such ring being fixed to the outer of two telescoping cylinders hung within the cylindrical shell 86. A roller bearing 92 at the bottom of the shell and a thrust bearing 93 at the top provide a rotary journal for said outer cylinder, designated by 94. At the low limit of telescoping travel the inner of said cylinders, denoted by 95, is secured against rotation relative to the outer cylinder by coupling rings 91 and 99 presenting interlocking teeth.

Fitted in the bottom end of the inner said cylinder 95 and secured thereto is a head 96, and fixed in a center opening of this head is a bushing 97 serving as a slide journal for a hollow spindle 98, the spindle having a spline fit in the bushing. The spindle presents a collar 100 at or about its mid-length, and secured to the collar at diametrically opposite sides of the spindle are the lower ends of a pair of piston rods 101.

At the lower end of the spindle there is provided a stud-gripping chuck. The nature of this chuck and the manner of attaching the same to the spindle can be best understood from an inspection of Figs. 16 through 23 wherein it will be seen that a chuck body 103 is secured by bolts 104 to the spindle, with an intervening spider 105. Radiating arms 106 of the spider are caught in registering notches of said body and the spindle. The spider presents an internally grooved hollow neck 107 extending into a head bore of the chuck body, and finding a loose spline connection in these grooves 102 is a set of cross-slats 108 gripped by bolts 109 between a headpiece 110 and a follower 111. The follower presents an upstanding hub, and a piston rod 112 is threaded by its lower end into this hub. The piston 113 which is related to said rod is double-acting and works in an oil cylinder 119 bolted in place within the hollow center of the spindle immediately above the spider.

The oblong socket of the chuck body previously referred to into which the reduced head 52 of the stud is received is denoted by 114, and above this socket is a recess 11-5 of relatively extended length. The diameter of this recess is appreciably larger than the span across the minor axis of the socket 114, and connecting the side walls of the socket with the side walls of the recess are flanks 116 sloped to an approximate 90 angle. The head-piece 110 occupies the upper end of the recess 115, and there is pivotally suspended from the head-piece a pair of opposed fingers 118 each having at its lower end an inturned jaw 120 arranged to fit the notches 54 of the studs and upon its underside presenting a sloped face 121 conforming to and adapted to ride along the sloping flanks 116 of the recess 115. Pins 122 urged outwardly by a spring 123 act to yieldingly spread the fingers. When the fingers are pushed downwardly by hydraulic action of the piston 113, the sloped flanks of the recess close the jaws upon the stud and it will be apparent that these flanks then lock the jaws upon the stud, taking all lateral thrust so that the piston itself is entirely relieved of stress when pull force is being exerted upon a stud in breaking the bond between the stud and the carbon block of the reduction cell.

Hydraulic fluid for the operation of the piston 113 is fed to opposite ends of the cylinder 119 by flexible hoses 125 and 126, these hoses extending upwardly the length of the spindle into the hollow interior of the cylinder 95, and thence being guided by rollers 127 over a goose-neck 128 to respective spring-loaded reels 130 and 131. A hub 129 which is common to these two reels is drilled to provide oil passages leading to the root ends of the two hoses. Flexible hoses 132 and 133 leading from a multiple unit control valve 134 connect by the usual fittings with said drilled passages. The goose-neck has its inner end, and which is to say the end opposite the reel, boltably secured to the crank ring 90, hence causing the goose-neck and its supported reel to swing bodily in uni 6 r son with the ring as quarter-turn wrist movements are imparted to the latter.

For the hydraulic activation of the spindle 98 in imparting controlled endwise motion thereto, and for hydraulically activating the cylinders 94 and in the controlled telescoping of the latter, there is provided within the inner of said cylinders two pairs of vertically disposed oil cylinders and one pair of vertically disposed transfer cylinders. Designated by 135, one pair of such oil cylinders are stationary, being placed diametrically opposite one another and having their upper ends anchored, as by bolts 137, to a plate 138 hung from a retainer ring 140. Pistons 142 which work in these cylinders are doubleacting and connect by piston rods 143 with the head 96 of the inner of the two telescoping cylinders. A hose 144 connects by branch pipes 145 with the lower ends of both stationary cylinders, and a hose 146 connects by branch pipes 147 with the upper ends of these cylinders. As will, it is believed, be apparent, the function of said stationary oil cyilnders is to expand and contract the telescoping cylinders 94 and 95. The second pair of the abovementioned oil cylinders, denoted by 150, act to impart endwise motion to the spindle 98 and, like the oil cylinders 135, are housed Within the inner cylinder 95 and are placed diametrically opposite one another. Cylinders 150 foot upon and are boltably anchored to the head 96, hence move with the latter, and double-acting pistons 151 for these cylinders connect by the referred-to piston rods 101 with the fixed collar 100 of the spindle 98.

In compensation of the vertical travel of which said movable cylinders 150 partake as the latter move with the head 96, pressure oil fed thereto is delivered through the pair of transfer cylinders which are denoted by 152 and 153. Each such cylinder is anchored by its lower end to the head 96 and has fitted therein a piston 159 presenting about its periphery a plurality of throughopenings 154 (see Fig. 15), thus permitting oil within the cylinder to flow freely between opposite ends thereof. A respective hollow piston rod 155 extends upwardly from each piston through a suitable end seal and has its upper end anchored to the stationary head plate 138, there connecting by a pipe terminal 156 with a related pressure hose, as 157 and 158. Respective pipe branches 160 and 161 connect with the lower ends of the transfer cylinders, one leading to the lower ends and the other leading to the upper ends of the two movable oil cylinders 150. Each of the hoses 144, 146, 157 and 158 are preferably of a type reinforced by a metal screen, as

are hoses 162 and 163 which lead to the inner and to the outer ends, respectively, of the two horizontal oil cylinders 88. Within the length of each of these reinforced hoses there is introduced an electric insulator, as.

164 (Fig. 37).

As will be seen from the diagram, each of the two horizontal oil cylinders 88, the stationary vertical oil cylinders 135, and the cylinder 119 for the chucking fingers are controlled by the multiple unit valve 134. An open center 4-way valve 165 controls the movable vertical oil cylinders 150. Hydraulic supply lines leading to said valves from a pressure source 166 are denoted by 167 and 168, and return lines are designated by 170 and 171. Incorporated in the circuit are the usual heat exchanger 172, relief valves 173, and balance valves 174. indicates an accumulator, 176 a pressure gauge, and 177 a pressure switch. This switch, which responds to the pressure within the oil line 133 which leads through hose 1'25 to the upper end of the oil cylinder 119, closes a normally open electric circuit including a signal light 169, evidencing within the line a pressure at or above a predetermined adequate intensity, say SO0#. Contained in the oil line 132- (see Fig. 37) which connects by hose 126 with the lower end of said oil cylinder is a solenoidoperated normally-closed valve 178. This valve closes,

the line only for out-flow travel of oil. Return-flow oil 

1. IN AN ALUMINUM REDUCTION PLANT HAVING MULTIPLE REDUCTION CELLS EACH OF WHICH EMPLOYS A PLURALITY OF VERTICALLY DISPOSED CURRENT-CONDUCTING STUDS, SAID STUDS HAVING THEIR LOWER ENDS SET INTO A CARBON BLOCK AND HAVING THEIR UPPER ENDS REMOVABLY CLAMPED TO A BUS BAR, THE STUDS EACH PRESENTING A HEAD WHICH IS NON-CIRCULAR IN SECTION AND HAVING A CROWN PORTION OF SAID HEAD UNDERCUT WITH V-SLOTS IN EACH OF THE OPPOSITE SIDES THEREOF, THE COMBINATION WITH SAID CELLS AND THEIR STUDS OF A TRAVELING CRANE MOUNTED FOR OVERHEAD MOVEMENT ABOVE SAID CELLS, A TROLLEY CARRIED BY THE CRANE AN MOVABLE TRANSVERSELY THEREOF, A VERTICALLY DISPOSED CYLINDRICAL SHELL CARRIED BY SAID TROLLEY, A FIRST CYLINDER MEMBER JOURNALED WITHIN THE SHELL FOR ROTATION ABOUT THE CENTER OF THE LATTER AS AN AXIS AND SECURED AGAINST ENDWISE MOTION WITH RESPECT THERETO, A SECOND CYLINDER MEMBER JOURNALED FOR ENDWISE SLIDING MOVEMENT WITHIN THE FIRST CYLINDER MEMBER, MEANS OPERATIVELY ASSOCIATED WITH SAID FIRST AND SECOND CYLINDER MEMBERS ACTING TO HOLD SAID SECOND CYLINDER MEMBER AGAINST ROTATION WITH RESPECT TO THE FIRST CYLINDER MEMBER WHEN THE LATTER REACHES ITS LOW LIMIT OF TRAVEL, A SPINDLE JOURNALED FOR ENDWISE SLIDING MOVEMENT WITHIN THE SECOND CYLINDER MEMBER AND HELD AGAINST ROTATION RELATIVE THERETO, A CHUCK UPON THE LOWER END OF SAID SPINDLE HAVING A DOWNWARDLY FACING SOCKET FORMED IN MATING CORRESPONDENCE WITH SAID NONCIRCULAR HEAD OF THE STUD AND, ABOVE AND COMMUNICATING WITH THE SOCKET, PRESENTING A RECESS OF EXPANDED WIDTH CONNECTING WITH THE SIDE WALLS OF THE SOCKET BY SLOPING FLANKS, THE CROWN PORTION OF THE STUD HEAD PROJECTING INTO SAID RECESS, CHUCK JAWS RECEIVED FOR VERTICAL MOTION WITHIN THE RECESS WITH LOWER FACE PORTIONS THEREOF RIDING ALONG SAID SLOPING FLANKS AND BY ACTION OF THE LATTER AS THE JAWS MOVE DOWNWARDLY WITHIN THE RECESS CAUSED TO CLOSE UPON AND ENGAGE IN THE SLOTS OF THE STUD HEAD, POWER MEANS OPERATIVELY ASSOCIATED WITH THE CHUCK JAWS FOR RAISING AND LOWERING THE CHUCK JAWS, MEANS YIELDINGLY SPREADING SAID JAWS SO THAT THE LATTER WILL OPEN IN RESPONSE TO SAID RAISING OF THE JAWS POWER MEANS OPERATIVELY ASSOCIATED WITH THE CRANE AND THE TROLLEY FOR REGULATING THE MOVEMENT OF THE CRANE AND THE TORLLEY SO AS TO BRING THE SOCKET OF THE CHUCK INTO VERTICAL REGISTRATION WITH THE HEAD OF A SELECTED STUD WHICH IS TO BE PULLED, AND POWER MEANS OPERATIVELY ASSOCIATED WITH THE TWO CYLINDER MEMBERS AND THE SPINDLE FOR TELESCOPING THE TWO CYLINDER MEMBERS AND THE SPINDLE SO AS TO RAISE AND LOWER THE CHUCK AND FOR TURNING THE FIRST CYLINDER MEMBER SO AS TO TWIST THE CHUCK. 